The idea that any individual market can only support a small number of wireless carriers gained support today with U.S. Cellular’s announcement that it would sell assets in some of the nation’s largest metro markets to Sprint. U.S. Cellular is selling its Chicago, St. Louis, central Illinois and three other Midwest markets to Sprint for $480 million.

But none of this prevented U.S. Cellular from obtaining what it called an “attractive valuation” of $820 per subscriber – and that’s not surprising, considering the wireless market’s apparently insatiable demand for spectrum.

U.S. Cellular, meanwhile, is left with numerous markets in rural areas and smaller metro markets, where the company may have fewer competitors.

The Sprint- U.S. Cellular deal is the latest example of the wireless industry’s ongoing reshuffling of spectrum and other assets. Verizon recently purchased unused spectrum from several of the nation’s largest cable companies, while AT&T has a range of deals pending to acquire more spectrum. And T-Mobile is hoping to acquire MetroPCS.

The Sprint- U.S. Cellular transaction is subject to regulatory approvals and is expected to close in mid-2013.